#include<iostream>
using namespace std;
const int N = 2010;
int n, m, k;
int f[N][N];
int main()
{
	cin >> n >> m >> k;
	for (int i = 1; i <= n; i++) {
		f[i][0] = 1;
	}
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= i; j++) {
			f[i][j] = f[i - 1][j] + f[i - 1][j - 1];
		}
	}
	if (!k) {
		cout << m << endl;
	}
	else {
		cout << (n - 1) * f[m][k - 1] << endl;
	}
	return 0;
}